MADRID — Spain's Socialists are determined to give acting Prime Minister Mariano Rajoy a taste of his own medicine at next week's investiture vote in Congress, even if it means subjecting the country to its third general election in just over a year — on Christmas Day.

The 85 MPs from the Spanish Socialist Workers' Party (PSOE), still bitter at their leader Pedro Sánchez's failure at the last investiture vote six months ago, will prolong eight months of political paralysis if they stick to their promise to vote against Rajoy.

At the same time, Sánchez has failed to give a coherent explanation of what the alternative would be to a government led by Rajoy’s conservative Popular Party, leaving Socialist party cadres, the PSOE leader's rivals and the country at large guessing at his motivation.

“We’ve got nothing in common with Rajoy,” was the explanation from Iratxe García, a member of Sánchez's leadership team and an MEP.

From the PSOE's point of view, the experience of other Social Democrats across Europe — in particular Germany's SPD — suggests that supporting conservative-led 'grand coalitions' can come at a very high political price. Such parties, said García, have subsequently “lost the capacity to be seen as an alternative for government.” At the last two votes, in December and June, Sánchez's Socialists narrowly avoided being beaten into third place by Pablo Iglesias' far-left Podemos.

Rajoy, cautious by nature, came first in December and June's elections but failed both times to secure a majority and was reluctant to risk a failed investiture vote — hence his rejection of King Felipe's offer in January to seek Congress' approval for a PP-led government.

Last week, Albert Rivera of the centrist Ciudadanos forced Rajoy into talks on a coalition deal that would give a potential center-right coalition 169 votes (the PP's 137 seats and 32 from Ciudadanos) — seven short of a majority. The support of a small regional party from the Canary Islands would bump that up to 170 — against 180 'no' votes from the PSOE, the far-left Unidos-Podemos alliance, and regional forces from Catalonia and the Basque Country.

If Rajoy fails, as expected, Spain's political parties will have two months to break the impasse: If no one succeeds by October 31, new elections will be called on December 25 — an unpopular date which prompted the Socialists to accuse the PP of blackmail.

At the same time, Ciudadanos — which came a disappointing fourth in June's vote — is able to project itself as an "unblocking tool" in the Spanish political impasse, in the words of the party's leader in Madrid, Ignacio Aguado. The many points in common between the suggested deal with the PP and the tentative agreement that Ciudadanos made with the PSOE in February would make it harder for the Socialists to justify their rejection this time around, he said.

Tribal behavior

If the PSOE's deputies abstain in next week's vote, thereby facilitating a PP-Ciudadanos deal, Iglesias of Podemos would be quick to portray himself as the only truly leftist alternative.

“The Socialists are already visualizing Pablo Iglesias on TV day in, day out saying Rajoy is still in power thanks to the PSOE,” said Manuel Arias, a politics professor at the University of Málaga.

PSOE voters are deeply divided about what course of action to take. Felipe González, Spain's Socialist prime minister from 1982 to 1996, wants Sánchez and his deputies to abstain in order to facilitate a PP-led government, in the national interest. But in an opinion poll in El Mundo newspaper this week, over half of PSOE voters judged such a move as middling to very bad.

Any Socialist considering challenging Sánchez for the leadership would have to confront him in an internal party vote.

Arias said this is the result of decades of the PSOE instigating “extreme tribal partisanship" that portrayed the PP as virtually fascist enemies far to the right of their European peers.

But the blocking strategy also responds to Sánchez's personal concerns.

The 190,000 card-carrying PSOE party members are far more fervent in their dislike of the PP than the average socialist voter. And they wield enormous power from which Sánchez himself has benefited in the past — in 2014, he became the first PSOE general secretary to be directly voted in by party members, a rare feat among the traditional Spanish political parties.

Any Socialist considering challenging Sánchez for the leadership would have to confront him in an internal party vote, meaning they'd have to vote for a party congress within a year to try to oust him. Any potential candidate who had openly advocated for facilitating a second term for Rajoy would have a hard time, which explains the current eerie silence.

“The regional presidents who think this is all crazy don’t want to be crucified by the people in the public square,” said a source inside the party's Federal Committee, who believes Spain is heading for new elections — and that the PSOE will take the blame.

“Sánchez is using his ‘no’ to Rajoy to grow stronger with party members,” said Lucía Mendez, political analyst for El Mundo. “Regional leaders opposed to him believe he’s leading the PSOE into an untenable situation, but they don’t have the courage to put up a public fight.”

Few options

To avoid that scenario, Sánchez will either have to change his mind about vetoing Rajoy or propose a viable alternative coalition before October 31. Inside a divided and confused party, where Sánchez and his leadership team are described as alienated from regional leaders, his chances are seen as minimal.

“The PSOE can’t build up any alternative coalition — it’s totally impossible,” said one senior party source, reflecting a view expressed by many Socialist cadres and observers consulted by POLITICO.

They rate his chances of securing a three-way deal with Podemos and Ciudadanos, which he tried in vain in March, as equally slim, with Rivera currently negotiating with the PP and very unlikely to reach an agreement with Podemos on anything but the need to combat corruption, where the two smaller parties see eye-to-eye.

On economics and the territorial unity of Spain, Rivera and Iglesias are poles apart. Likewise, the PSOE has a drastically different agenda to Unidos-Podemos and the Basque and Catalan regional parties on self-rule, at a moment when Catalonia's regional government is dead set on a referendum on independence from Spain.

Carles Campuzano, a deputy in congress for the recently re-founded Partit Demòcrata Català — the party of Catalan regional President Carles Puigdemont — said a referendum was a non-negotiable condition for any coalition deal, though it wouldn't necessarily have to be binding as that would require constitutional changes that are impossible without the support of the pro-unity PP. Caumpuzano said he would like the PSOE "to have the courage" to go down this path, but feared the Socialists had become "very conservative in this regard."

The senior PSOE source said there was no way the party would allow such a "crazy" idea, even if Sánchez was tempted to try to link up with pro-independence forces — an option the PP dismisses as a "Frankenstein government."

Basque and Galician gambits

One game changer could arrive on September 25, when there are regional elections in the Basque Country and Galicia. The PP is defending its governing majority in Galicia, where the local Podemos alliance and PSOE have an outside chance of combining forces to oust Rajoy's candidate — and this could improve the chance of leftist cooperation at the national level.

In the Basque Country, the Basque Nationalist Party (PNV) is currently in power with PSOE support, but Podemos' success in the region in June's national election threatens to change the status quo — and potentially force the PNV to seek the PP's support. In return, Rajoy would demand reciprocity at the national level, improving his numbers in Congress.

For political consultant Iván Redondo, these two regional elections could trigger a fresh bid for investiture by Rajoy or Sánchez in October.

“This time Sánchez has copied Rajoy’s strategy,” said Redondo, referring to the conservative leader's characteristic wait-and-see attitude. “And it could work out well for Sánchez.”

"All factors on the table are driving us towards new elections” — Lucía Mendez, political analyst for El Mundo

For Redondo, the Socialists must find a way to fend off the challenge in regions like Catalonia and the Basque Country from Podemos, whose embrace of self-determination has enabled it to poach votes from the Socialists and traditional regional players.

If on the other hand Rajoy joins forces with the PNV in the Basque Country and secures their support in Congress, he would have 175 seats and destroy the PSOE's chances of forming an alternative coalition — making it easier for Sánchez to argue that there is no alternative to an abstention and a PP-led minority government. To share out responsibility for such a move, he would probably call a meeting of the PSOE leadership to force his rivals to declare their hand.

The longer it takes Sánchez to decide, the tougher the choice will be, said Méndez at El Mundo, concluding that "all factors on the table are driving us towards new elections.” Politics professor Arias sees it all coming down to last-minute private poll commissioned by the PSOE: If that indicates to Sánchez that a new election is riskier than abstaining and allowing Rajoy a new term, Spain may have a chance of avoiding a Christmas Day ballot.

However, if Spain does end up going the ballots for the third time in short succession, there is a bright side, argued Socialist MEP García: “Many generations in this country spent a long time without being able to vote."